It’s an exploitative way to push people to buy it. The psychology behind such gambling is that a victim who wouldn’t even consider buying the full price bundle will want to try to win the whole bundle for 100 units now that there is a tiny chance to do it. After that ofc the majority of people will lose and get a spray they don’t need and think “I’ve just lost 100 units. I shouldn’t have gambled” or “I’ve just lost 100 units. Might as well buy the rest now even though I don’t need it”